"The high court has said the charges were flawed and, therefore, should be set aside," his lawyer Perpetua Dube told AFP.

She said the judge had ruled on Thursday that the charges "did not constitute an offence".

"It's a great relief for Mr Bronkhorst," said Ms Dube.

The ruling followed an application by Mr Bronkhorst's lawyer for a review of a previous decision by a magistrate's court to have him tried over the 2015 hunt which led to the death of the lion renowned for its distinctive black mane.

Professional hunter Theo BronkhorstCredit:
Tsvangirayi Mukwazhi/AP

The hunt provoked worldwide outrage after it emerged that Cecil was not only a popular attraction for visitors to Hwange National Park, but that he wore a collar as part of an Oxford University research project.

Mr Bronkhorst, 53, had been charged with "failing to prevent an illegal hunt" when American trophy hunter Walter Palmer, a dentist, paid $55,000 to shoot the lion with a bow and arrow in July last year.

Zimbabwe decided not to charge Mr Palmer after it emerged he had legal papers allowing him to hunt.

Mr Bronkhorst denied any wrongdoing, saying he had the required permits to kill an elderly lion that was outside the national park boundaries. Cecil, who was 13 years old, was killed outside the reserve, which is not fenced.